Cycads resemble palms, but are taxonomically quite different. They are a significant and irreplaceable component of the planet's biological diversity, having evolved various and often unique morphological, anatomical and biochemical features during their 250-million-year evolutionary history. Many cycad species exist today only as small, poorly-known or isolated populations or as ornamental species in botanic gardens. In order to understand fully, as well as to conserve, this internationally endangered tropical plant group, it is paramount that cycad systematics are studied, documented and refined. This volume presents the current state of our knowledge of the systematics of the approximately 300 species of cycads. It includes contributions from leading researchers from Australia, China, Italy, Mexico, South Africa, Thailand and the USA. It has been developed from papers presented at a workshop held in 2002, at the Montgomery Botanical Center.
Author(s): Terrence Walters, Roy Osborne
Edition: First
Publisher: CABI
Year: 2004
Language: English
Pages: 304
Contributors......Page 7
About the Editors......Page 9
Preface......Page 11
Acknowledgements......Page 15
1 ‘We Hold these Truths …’......Page 19
2 Saving Ghosts? The Implications of Taxonomic Uncertainty and Shifting Infrageneric Concepts in the Cycadales for Red Listing and Conservation Planning......Page 31
3 Character Evolution, Species Recognition and Classification Concepts in the Cycadaceae......Page 41
4 Morphological Characters Useful in Determining Species Boundaries in Cycas (Cycadaceae)......Page 63
5 Comments on Cycas, Dyerocycas and Epicycas (Cycadaceae)......Page 75
6 Classification Concepts in Encephalartos (Zamiaceae)......Page 87
7 Classification Concepts in Macrozamia (Zamiaceae) from Eastern Australia......Page 103
8 Classification Concepts in Ceratozamia (Zamiaceae)......Page 113
9 Relationships and Phytogeography in Ceratozamia (Zamiaceae)......Page 127
10 A Morphometric Analysis of the Ceratozamia norstogii Complex (Zamiaceae)......Page 145
11 Hypotheses on the Relationship between Biogeography and Speciation in Dioon (Zamiaceae)......Page 155
12 Molecular Phylogeny of Zamia (Zamiaceae)......Page 167
13 Systematics of Meso-American Zamia (Zamiaceae)......Page 177
14 Zamiaceae of Bolivia, Ecuador and Peru......Page 191
15 In Search of the True Tree: Guidelines for Classification......Page 213
Appendix 1: The World List of Cycads......Page 237
Appendix 2: Glossary of Terms Encountered in Cycad Systematics......Page 255
